1. Field of the Invention
The present invention relates to the improvement of a throttle regulator for use in a vibration compaction machine such as a rammer, for compacting a road surface by hitting the road surface with a compaction plate that moves up and down.
2. Description of the Related Art
A vibration compaction machine such as a rammer is loaded on a vehicle and transported before the operation is started and after the operation is completed, but if the machine is loaded in a sidewise state, there is a risk of the fuel leaking from a fuel tank into a carburetor and causing an accident by ignition and explosion.
To resolve this problem, in prior art, a structure was disclosed in which once the compaction machine has ended the operation and an engine has been stopped by manipulating a throttle lever, a channel for supplying a fuel from a fuel tank to the engine was automatically closed to cut off the fuel leak. As a result, the occurrence of accidents associated with fuel leak could be prevented.
Such throttle regulators are configured so that fuel leak can be prevented by actuating an engine stop switch and a fuel cock by turning a throttle lever, but the problem associated with the conventional throttle regulators is that the engine stop switch, fuel cock, and throttle lever speed regulation mechanism are not provided together on a manipulation handle of a compaction machine so that they can be easily enabled by a operator. As a result, the engine stop switch and fuel cock can hardly function adequately.
For example, in the throttle regulator described in Japanese Patent Application Laid-open No. 9-195855, the fuel cock valve mechanism is directly connected to the throttle lever, but the engine stop switch is provided so as to be actuated by a push-button switch that is operated by a wire attached in a position separate from that of a wire for turning the throttle lever, for example, on the engine body side. The resultant problem is that the push-button switch cannot be enabled unless the wire for the turning manipulation of the throttle lever is smoothly actuated.
In the throttle regulator of Japanese Patent Applications Laid-open No. 2001-200734, various units such as a throttle mechanism, an engine stop switch, a fuel cock valve mechanism, and a fuel tank inner pressure release valve are configured by using a fuel tank as the base component. As a result, such units as the throttle mechanism and engine stop switch are provided on the surface of the fuel tank that is easily contaminated at all times with dust or the like. On the other hand, the fuel cock valve mechanism and fuel tank inner pressure release valve are provided inside the fuel tank that cannot be easily disassembled and, therefore, those mechanisms are difficult to maintain. Yet another problem is that because the surface of the fuel tank is positioned in the zone above the operation handle, one-hand operation is performed when the throttle lever is manipulated, and the units are difficult to manipulate.
Furthermore, in the throttle regulators described in Japanese Patent Applications Laid-open No. 9-195855 and 2001-200734, piston-type valves are used as the fuel cock valve mechanism and, therefore, one of the open-closing operations in the valve mechanism relies upon a spring force. However, when such piston-type valve mechanism relying upon a spring force is used over a long period, the fuel that adhered to the valve mechanism is converted into a resinous substance that causes malfunction in the opening-closing operation of the valve and also a valve seal surface is damaged due to the adhesion of foreign matter or the like.